1. you must move the decimal the amount of digits until the divisor is a whole number. This also means that you move the decimal for the dividend too, adding zeros where it is needed. 2. you must first figure out where the decimal is, so that you will find out what place value each digit is, allowing you to add correctly. For example 10.52 + 0.048 = 10.568 3. you determine it by the amount of digits from the right it is, and moving it to the correct place. For example 10.5 x 20.25 = 212.625 (note that for this example, the decimal moved to the left 3 spaces)
you would divide the number of times the coin landed on heads by the total times thrown which give s you .3857 you move the decimal over twice to give you 38.5 and round up to 39%